Berries Production Guide

Blueberries
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Insects

This section was updated - 26 June 2017

Insecticides such as Admire, Assail, Actara, Decis and Malathion are toxic to bees. Do not apply them during the blossoming period.

Note: The recommended spray rates are for mature bushes unless otherwise specified. For smaller, immature bushes use reduced amounts of spray mixture.

Aphids

Hosts

All blueberry varieties are susceptible to aphid attack.

Damage

Most aphids are found on new shoot growth where they feed by sucking sap. Aphid numbers are seldom high enough to weaken or stunt growth by removing sap. Occasionally high aphid levels occur, slowing growth, reducing yields, and making berries sticky with honeydew and sooty mould.

Aphids spread blueberry scorch virus which, in infected plants, is at highest levels during the spring. Greater aphid numbers mean increased potential for virus spread by wingless aphids that walk between plants within a row and by winged aphids that fly between rows. Recent research suggest that most of the virus transmission occurs in June and early July when populations of resident aphids on blueberry are at peak density and large flights of migrant aphids occur.

beetle

Identification

Almost all (over 98%) aphids on blueberries are Ericaphis fimbriata. This is a small to medium-sized aphid (adults 1-2 mm), with yellowish green or red nymphs, green or red wingless adults and black winged adults. They are found singly or in colonies, on opening flower or leaf buds in March, and on the under-surface of new leaves in the spring, and new and old leaves in the summer.

Life History

Aphids over-winter as black eggs (0.5 mm long) on stems near buds, and in the leaf litter. In the Fraser Valley the eggs hatch from late February to the end of March, when the buds start to open. Young wingless aphids (nymphs) will feed on unopened buds, then on blossoms and growing shoots. Asexual reproduction (daughter-to-daughter) for several generations results in rapid population increase. Winged adults are produced all season starting in early May. Populations peak from mid-June to mid-July and subsequently decline naturally through a reduction in plant quality which affects aphid birth and development rates, and through biological controls. Sexual aphids are produced in September. These mate and produce eggs in October.

Monitoring

Over wintering aphids are very difficult to detect in the spring as they are within buds and developing blossom clusters. To effectively control the spread of virus, a pre-bloom spray is recommended to prevent populations from building later in the season. See Chemical Control below.

Monitoring should begin during the latter part of bloom to determine if post-bloom sprays are required. Check the top 30 cm of growth on 10 branches per plant. Consider treatment if 30% or more of the tips have aphids.

Management

Cultural control

Excessive growth caused by too much N favours a build up of aphids.

Biological control

A number of native beneficial insects feed on and parasitize aphids. These include ladybird beetles, syrphid larvae, lace wing larvae, and small parasitic wasps. The decline in aphid populations during July and August is caused partly by beneficial insects. Most insecticides will damage native beneficials so they should be used only when necessary.

Chemical control

If blueberry scorch virus is present, or if it exists within the area, chemical aphid control is recommended in April, pre-bloom, to reduce the rate of spread. If all growers effectively control the over wintering generation it will help prevent aphid populations from building later in the season. This spray is timed after all aphid eggs have hatched, and before winged forms are produced. Additional sprays after bloom may be required if few beneficial insects are present and aphid populations are increasing. The following products are recommended:

Pre or Post Bloom Application

Fulfill 50WG (50% pymetrozine) at 193 g/ha (77 g/acre) as a foliar spray before bloom to control overwintering aphids. Use in enough water to obtain good coverage (500 to 1000 L/ha). Treat fields infected with blueberry scorch virus and adjacent fields at risk of infection. A second application may be made post harvest if aphid numbers warrant. Do not apply more than twice per season. Do not apply within 85 days of harvest; or

Exirel (100 g/L cyantraniliprole) at 750 to 1500 mL/ha (300 to 600 mL/acre) in enough water to obtain good coverage. Use the high rate when pest pressure is heavy. Do not apply during bloom as Exirel is toxic to bees. Do not apply more than 4 times per season or a maximum of 4.5 L/ha (1.8 L/acre). Tank mixes and sequential applications with strobilurin (Pristine, Cabrio), copper and captan fungicides are not recommended as crop injury has resulted under lab settings. Do not apply within 3 days of harvest; or

Sivanto Prime (200g/L flupyradifurone) at 500-750 ml/ha (196-295 ml/acre) in a minimum of 100 L/ha (40 L/acre) of water as a directed foliar spray. Do not apply more than once every 7 days. Do not exceed 2000 ml/ha (787 ml/acre) per season. Do not apply within 3 days of harvest; or

PyGanic EC1.4 (1.4 % pyrethrins) at 2.32 to 4.65 L/ha (0.93 to 1.86 L/acre) in enough water to ensure complete coverage of all plant surfaces. Apply promptly after mixing. Do not reapply within 7 days. Do not apply more than 8 times per season. It may be applied up to the day of harvest. It is OMRI approved for organic production.

Post Bloom Application Only

Admire 240F or Alias 240SC (240 g/L imidacloprid) at 175 mL/ha (70 mL/acre) as a foliar spray in enough water to obtain good coverage (up to 1000 L/ha). Apply after bloom after bees have been removed from the field when aphids numbers are increasing. Do not apply more than 2 times per crop per season. Allow at least 7-10 days between applications. Do not apply Admire within 3 days of harvest. Do not apply Alias within 14 days of harvest; or

Concept Liquid (75 g/L imidacloprid, 10 g/L deltamethrin) at 560 mL/ha (224 mL/acre) in enough water to obtain good coverage. Apply post bloom after bees have been removed from the field if aphid numbers are increasing. Concept will also control caterpillars. Do not apply more than 3 times per season. Allow at least 5 days between applications. Do not apply within 14 days of harvest; or

Note: Concept is not acceptable for some markets. Check with your packer before using.

Assail 70WP (70% acetamiprid) at 56 to 86 g/ha (22 to 34 g/acre) in a minimum of 187 L/ha (75 L/acre) of water by ground application. Do not apply more than 4 times per season. Do not apply more than once every 12 days. Do not apply during bloom as Assail is toxic to bees directly exposed to treatment. Do not apply within 7 days of harvest; or

Movento 240 SC (240 g/L spirotetramat) at 220 to 365 mL/ha (88 to 146 mL/acre) in enough water to obtain good coverage. Apply post bloom after bees have been removed from the field when aphids numbers are increasing. Use the higher rate when pest pressure is heavy, canopy is heavy or insect development is extended (cool weather). Do not apply more than a total of 1.8 L/ha (0.72 L/acre). Allow at least 7 days between applications. Do not apply within 7 days of harvest.

Blueberry Midge

Hosts

Blueberries, cranberries.

Damage

Larvae feed in the growing tips of the plant causing excessive branching of new growth. This is particularly a problem in young plantings as bushes may be slower to reach adequate height for machine harvesting. Midge damage and resulting branching may be less important in older plantings.

Identification

The adult is a very small midge-like fly. The tiny larvae (maggots) are clear (first instar) or greenish-white (second instar) or orange (third instar), with no visible head. The third and last instar maggot is about 2 mm long. Pupae are enclosed in a silken cocoon in the damaged tip.

Life history

This insect over-winters as a pupa in the soil, and in mid-April the adult fly emerges and begins laying eggs in the growing tips of the plants. Each female lays 35 to 40 eggs. The life cycle from egg to adult takes 22 to 25 days, so there are several generations a year. Generations may overlap and all stages may be present together on one plant.

Monitoring

Examine growing tips for signs of distortion and discoloration. Inspect growing tips with a hand lens and tease apart to see maggots.

Management

Chemical control 

Movento 240 SC (240 g/L spirotetramat) at 365 to 435 mL/ha (146 to 174 mL/acre) in enough water to obtain good coverage. Apply post bloom after bees have been removed from the field when hatching midge eggs are detected. Use the higher rate when pest pressure is heavy, canopy is heavy or insect development is extended (cool weather). Do not apply more than a total of 1.8 L/ha (0.72 L/acre) per season. Allow at least 7 days between applications. Do not apply within 7 days of harvest; or

Exirel (100 g/L cyantraniliprole) at 750 to 1000 mL/ha (300 to 400 mL/acre) in enough water to obtain good coverage. Use the high rate when pest pressure is heavy. Do not apply during bloom as Exirel is toxic to bees. Do not apply more than 4 times per season or a maximum of 4.5 L/ha (1.8 L/acre). Tank mixes and sequential applications with strobilurin (Pristine, Cabrio), copper and captan fungicides are not recommended as crop injury has resulted under lab settings. Do not apply within 3 days of harvest.

CATERPILLARS (Leafrollers, Spanworms, Winter Moths and others)

Hosts

Berries, fruit trees, ornamental and native deciduous trees.

Damage

Spanworms and winter moth are primarily early season pests. They can cause severe crop loss in early spring by boring into swelling buds and feeding on petals and flower parts. They also chew on new leaf growth. Severe infestations, if not controlled, can result in complete loss of fruit production and total defoliation.

Leafrollers can cause similar damage, but usually occur later in the season. They feed on blossom and fruit clusters from late April through early June. The second generation larvae feed on leaves and berries and may become a contaminant in harvested fruit.

Identification

Bruce’s spanworms and winter moth


Larva: Light or dark green with pale lines along the body. About 1 cm at full length. Often arch their body when moving along a branch.

Adult: Wingless female rarely seen; male moth with thin wings banded with brown and grey.

Oblique banded leafrollers
catepillar

Eggs: Greenish masses of up to 150 eggs on leaves.

Larva: Caterpillars are light cream to dark green with brown to black heads and up to 12 mm long.

Adult: Moths are buff-coloured or grey with wing spans up to 2 cm. Various other caterpillar species can also feed on blueberries. Contact BCAGRI or your crop consultant to identify and assess damage.

Life history

Bruce’s spanworm and winter moth


Wingless females deposit eggs singly on trunks and stems of host plants in November and December. Tiny caterpillars (about 1 mm long) emerge in late March to early April. Larvae can be found on plants until early June when they drop to the ground. Larvae pupate in the soil and remain there until they appear as adults in November to December, to mate. There is one generation each year. Adults and larvae of both species look very similar and are usually present together.

Oblique banded leafrollers


The insect overwinters as eggs under loose bark or as small larvae. In April, larvae begin to feed on developing shoots and blossom clusters and roll up leaves. Feeding continues until late May to early June followed by pupation and moth emergence in late June to early July. Eggs are laid and a second generation of larvae feeds in July and August. The oblique-banded leafroller has two generations each year while other leafroller species may have one to three generations.

Monitoring

Examine buds, shoots and blossom clusters for larvae and feeding damage weekly beginning in late March. Spanworms spin silken threads. Leafrollers roll up leaves. Watch for feeding damage on new growth and within blossom clusters. Successful control depends on treatment shortly after egg hatch, before larvae bore into buds or get within blossom clusters. Treatments should be applied if more than 5% of the terminals and floral parts have larvae and/or damage.

Management

Cultural control

Pruning and good weed control helps to reduce numbers by removing over wintering sites.

Biological control

Native parasitic and predatory insects, as well as spiders can help to reduce caterpillar populations.

Bacillus thuringiensis, kurstaki (Foray 48BA, Dipel) is a bacterium that acts as a stomach poison against caterpillars. It is not toxic to bees or to other beneficial insects. See below for recommendations on its use.

Chemical control

A spring pre-bloom treatment is generally required if larvae and/or damage are found in more than 5% of terminals. An additional treatment may be required between the end of bloom and harvest to control second generation leafrollers that may damage or contaminate fruit.

Do not spray with products other than Bt during the blossom period to avoid killing bees.

Apply one of the following:

Group 3

Decis 5.0 EC or Decis Flowable (50g/L deltamethrin) at 125 mL/ha (50 mL/acre). Use in 1200 to 1500 L/ha (480 to 600 L/acre) of water. More concentrated application rates may cause crop injury. Do not apply by air. Very toxic to fish. Do not apply near ditches and water courses. Decis is toxic to bees. Do not apply during bloom when bees are actively foraging. Do not apply within 14 days of harvest; or

Note: Decis is not acceptable for some markets. Check with your packer before using.

Group 5

Delegate WG (25% spinetoram) at 100 to 200 g/ha (40 to 80 g/acre) at egg hatch or to small larvae. Use the higher rate for high populations and/or larger larvae. Repeat if necessary. Do not apply more than 3 times per year. Allow a re-treatment interval of at least 6 days. Delegate is toxic to bees. Do not apply during bloom when bees are actively foraging. Do not apply within 3 days of harvest; or,

Success 480SC (480 g/L spinosad) at 145 to 182 mL/ha (58 to 73 mL/acre) in 300 to 500 L/ha of water. Use the upper rate under high insect pressure and/or on large larvae. Do not apply during bloom when bees are actively foraging. Apply a maximum of 3 times per year and do apply within 3 days of harvest; or

Entrust 80W (80% spinosad) at 80 to 109 g/ha (32 to 44 g/acre) in 300 to 500 L/ha of water. Use the upper rate under high insect pressure and/or on large larvae. Apply a maximum of 3 times per year. Do not apply during bloom when bees are actively foraging. Do not apply within 3 days of harvest. Entrust is OMRI approved for organic production; or

Group 28

Altacor (35% chlorantraniliprole) at 215 to 285 g/ha (86 to 114 g/acre) in enough water to ensure good coverage. Use the high rate when insect pressure is heavy.  Do not apply during bloom when bees are actively foraging. Do not apply more than 3 times per season. Do not apply more than once every 7 days. Do not apply within 1 day of harvest; or

Exirel (100 g/L cyantraniliprole) at 500 to 1000 mL/ha (200 to 400 mL/acre) in enough water to obtain good coverage. Use the high rate when pest pressure is heavy. Do not apply during bloom as Exirel is toxic to bees. Do not apply more than 4 times per season or a maximum of 4.5 L/ha (1.8 L/acre). Tank mixes and sequential applications with strobilurin (Pristine, Cabrio), copper and captan fungicides are not recommended as crop injury has resulted under lab settings. Do not apply within 3 days of harvest; or

Group 18

Intrepid (240 g/L methoxyfenozide) at 0.5 L/ha (200 mL/acre). Apply when feeding damage is first detected. Repeat applications after 7-14 days if required. Do not apply within 7 days of harvest; or

Confirm 240 F (240 g/L tebufenozide) at 1.0 L/ha (0.4 L/acre) when young larvae or feeding damage is first detected. Additional applications at 10-14 days intervals may be required if pest pressure is heavy.  Do not apply more than 4.6 L/ha (1.8 L/acre) of product per season. Do not apply within 14 days of harvest; or

Group 1B

Imidan 50WP (50% phosmet) at 2.25 kg/1000 L of water/ha (0.9 kg in 400 L/acre) or Imidan 70WP (70% phosmet) at 1.6 kg/1000 L of water/ha (0.64 kg In 400 L/acre).  Do not apply during bloom when bees are actively foraging. Do not apply more than twice per year. Do not apply within 15 days of harvest; or

Group 1A

Sevin XLR Plus (466g/L carbaryl) at 4 L/ha (1.6 L/acre). Use 1200 to 1500 L spray/ha (500 - 600 L/acre). Do not apply during bloom when bees are actively foraging. Do not apply Sevin XLR Plus within 2 days of harvest; or

Group 11

Foray 48BA (Bacillus thuringiensis, Bt) at 4.0 L/ha in 600 L water/ha (1.6 L/acre in 240 L/acre water) or Dipel 2X DF at 0.525 to 1.125 kg/ha (210 to 450 g/acre) or Bioprotec 3P at 0.72 to 1.45 kg/ha (0.29 to 0.58 kg/acre). Apply when caterpillars are young. Use the higher rates when leafroller numbers are high or for mature     leafrollers. Apply in late afternoon or evening as Bt is sensitive to sunlight. It is not toxic to bees or to other beneficial insects. Fruit can be harvested on the same day as Bt is applied. Bt products are OMRI approved for organic production.

 

Tent Caterpillars and Fall Webworms

Hosts

Fruit and nut trees, and native trees including maple, birches, willow and poplar.

Damage

Leaves. Larvae feed in colonies on the foliage, often skeletonizing leaves and can defoliate entire young bushes.

Branches. Except for the forest tent caterpillar which does not build tents on blueberries, the larvae live in a messy web shelter built around a portion of the bush. Can interfere with picking.

Identification

Larva. Forest tent caterpillars have a row of white diamond shaped markings along the top of their bluish-grey bodies. Western tent caterpillars have a row of blue spots along the top of their bodies with orange spots on each side of that line. Their bodies are generally yellowish-brown, and hairy. Fall webworm caterpillars are covered with yellow-orange hair growing from black and orange bumps.


Adult. The adult form of these caterpillars are moths. They fly at night and are rarely seen.

Life History

The western tent caterpillars make tents from May to June whereas the fall webworm has tents from mid-July to mid-September. The forest and western tent caterpillars overwinter as rings of egg masses on one year old wood. The fall webworm overwinters in the pupal stage in debris on the ground or in the soil.

Management

Cultural control

Prune out twigs with egg masses during the dormant season.

Prune and destroy tents containing the caterpillars while tents are small.

Biological control

Bacillus thuringiensis (Dipel, Foray, Bioprotec) applied during the season to control other caterpillars will also control young tent caterpillars. Bt is not toxic to bees or other beneficial insects when applied during bloom.

Chemical control

There are no insecticides registered to control these pests on blueberries. Dormant oil sprays applied from January until mid-February to control scale will also kill tent caterpillar egg masses. Insecticide sprays applied to control other pests will also control young tent caterpillars. The fall webworm usually appears after harvest: control is not necessary unless populations are high. Spot treatments of infested bushes can be done.

Cherry Fruitworm

Hosts

Blueberry, cherry, other stone fruit, apple, hawthorn, rose

Damage

Larvae feed in developing fruit leaving tunnels and frass rendering it unmarketable.

Identification

Egg. Very small, flat, oval eggs laid singly on calyx of green fruit
Larva. White to pale pink with brown head, 7.5 to 9 mm long


Adult. Small moth (9-11 mm wing span) with dark grey and black wavy stripes (not distinct)

Life History

There is one generation per year. Moths emerge in spring and lay eggs on green fruit. Larvae hatch and burrow into developing fruit. Each larva will infest 1-2 fruit before exiting and searching for an overwintering site in early to mid-August. Larvae overwinter in silken structures in pruning stubs, wounds or under bark and pupate the following spring.

Monitoring

Currently, cherry fruitworm has only been detected in a few BC blueberry fields.

Search for eggs on green fruit from late May to mid June. Monitor for adults with pheromone traps from May to August. Research is underway in BC to further refine monitoring techniques.

Management

Cultural control

None

Chemical control

Insecticide sprays should be applied when eggs and small larvae are present, but before they have entered fruit. Based on BC information, this will be post bloom, during green fruit development. A second application should be made 10 - 14 days later. Research is underway in BC to better refine spray timing.  

Use:

Altacor (35% chlorantraniliprole) at 215 to 285 g/ha (86 to 114 g/acre) in enough water to ensure good coverage. Use the high rate when insect pressure is heavy. Do not apply more than 3 times per season. Do not apply more than once every 7 days. Do not apply within 1 day of harvest; or

Assail 70WP (70% acetamiprid) at 160 g/ha (64 g/acre) in a minimum of 190 L/ha (75 L/acre) of water by ground application. Do not apply more than 4 times per season. Do not apply more than once every 12 days. Do not apply during bloom as Assail is toxic to bees directly exposed to treatment. Do not apply within 7 days of harvest; or

Malathion 85E (85% malathion) at 550 mL/ha (220 mL/acre) or Malathion 25W (25% malathion) at 2.25 kg/ha (0.9 kg/acre). Spray bushes for thorough coverage. Do not apply within 1 day of harvest; or

Rimon 10EC (10% novaluron) at 1.35 to 2.0 L/ha (0.5 to 0.8 L/acre) in enough water to ensure good coverage. Use the higher rates and spray volumes when larvae are large or canopy is heavy. Avoid applying during bloom when bees are present. Do not apply more than 3 times per season. Do not apply within 8 days of harvest.

Confirm 240 F (240 g/L tebufenozide) at 1.2  L/ha (0.5 L/acre) when egg laying begins. Additional applications at 10-14 days intervals may be required if pest pressure is heavy.  Do not apply more than 4.6 L/ha (1.8 L/acre) of product per season. Do not apply within 14 days of harvest; or

Foray 48BA, or Dipel 2X DF (Bacillus thuringiensis, Bt). Apply Foray at 4.0 L/ha in 600 L water/ha (1.6 L/acre in 240 L/acre water) or Dipel at 0.52 to 1.13 kg/ha (210 to 450 g/acre). It is not toxic to bees or to other beneficial insects. Apply in late afternoon or evening as Bt is sensitive to sunlight. Apply when temperature is above 18oC and there is no threat of rain for at least 24 hours. The optimum solution pH for Bt is 6.0 -  some breakdown occurs above that point. Fruit can be harvested on the same day as Bt is applied.

Delegate, Entrust, Success and Decis used for other pests will also help to control cherry fruitworm if they are applied before larvae enter fruit.

Sawflies

Damage

Rarely cause significant crop damage.

Buds. Chewed buds and flower parts by larvae (slugs).


Leaves. Larvae feed on the underside of the older leaves, often leaving the upper layer and veins intact. Appears as brown patches on leaves.

Identification

Larva. Shiny, green, up to 5 mm long and resemble slugs.

leaf

Adult. Dark coloured wasps which may have some bright markings.

Monitoring

Watch for larvae when looking for leafrollers. Usually appear early in the season, maturing and disappearing by mid-bloom. A second generation occurs in late summer.

Management

Cultural control

Clean cultivation reduces numbers.

Chemical control

Caterpillar and aphid sprays will also control sawfly larvae. If damage is noticed close to the end of harvest or after harvest, no control is necessary.

Scale Insects

Hosts

Ornamental plants and fruit trees.

Damage

Scales suck the sap from the plants reducing plant vigour and terminal growth. Scales secrete honeydew which promotes the growth of a black sooty mould, makes picking unpleasant and may make fruit unsuitable for fresh market.

Identification

Oval, brown bumps up to 5 mm in diameter found on the previous seasons’ growth. Overwintering forms are found on new wood as 2 mm elongate, flat pale spots from September until early spring.

Life History

Overwintering forms complete development by late spring or early summer. White eggs are found under these scales in May or June. The eggs begin to hatch in late June to early July and the young scales (“crawlers”) migrate from under the females in July. They move to the underside of leaves and feed for 4 to 6 weeks before returning to the stems and twigs to overwinter. The scales mate in early spring and the females continue to feed until early fall. The males die after mating.

Monitoring

During the dormant season inspect plants and mark areas where many scales are seen. Start to check for egg hatch and crawler migration in May.

Management

Cultural control

Prune out and destroy heavily infested branches.

Chemical control

Apply controls during the following times:

Dormant season. To control overwintering scale. Generally this control is the most effective and easiest to apply. Apply during the late winter while the plants are fully dormant, usually during January until mid-February:

Dormant spray oil at 20 L/1000 L of water; or

Dormant Spray Oil at 12.5 L plus lime sulphur at 36.7 L in 1000 L of water Dormant oil kills scales by suffocation, therefore spray to the point of run-off to obtain good coverage. Apply spray when the temperature is above freezing.

Growing season. To control the young scale “crawlers”. If honeydew production is severe, apply during the growing season when the crawlers are active, usually late July through August. Use high pressure to ensure good coverage of the undersides of the leaves and the twigs.

Movento 240 SC (240 g/L spirotetramat) at 220 to 365 mL/ha (88 to 146 mL/acre) in enough water to obtain good coverage. Apply post bloom after bees have been removed from the field when aphids numbers are increasing. Use the higher rate when pest pressure is heavy, canopy is heavy or insect development is extended (cool weather). Do not apply more than a total of 1.8 L/ha (0.72 L/acre). Allow at least 7 days between applications. Do not apply within 7 days of harvest; or

Sevin XLR Plus (466 g/L carbaryl) at 4.0 L/ha (1.6 L/acre) in 1200 to 1500 L spray volume/ha (480 to 600 L/acre). Do not apply Sevin XLR Plus within 2 days of harvest; or

Sevin 50W (50% cabaryl) at 3.25 kg/500 L. Use 1400 to 1700 L/ha (560 to 680 L/acre) of water. Do not apply within 1 day of harvest.

Do not spray during the blossoming period to avoid killing bees. Bees sometimes forage on honeydew so apply sprays after bees return to the hives, if possible.

Spotted Wing Drosophila (SWD, D. suzukii)

Hosts

Berries, stone fruits and numerous wild hosts

Damage

Female flies lay eggs under the skin of ripe fruit. Larvae hatch and begin to feed within the fruit, causing softening in the area of feeding. There can be several larvae in a fruit, which hastens softening and fruit collapse. Holes the size of pin pricks are evident within the soft areas of infested blueberries.

Identification

Adults: 2-3 mm (1/8 inch) long, brownish with red eyes and clear fly-like wings. Males have a black/grey spot on the end of each wing, as well as two black ‘combs’ or bands on each front leg. The females do not have spots or leg bands. Females have saw-like egg-laying organs (ovipositors) that are used to cut into fruit skin. Ovipositors are easier to see when extended. A hand-lens or dissecting microscope is needed to identify ovipositor.

Eggs: 0.6 mm long, oval, white, 2 filaments at one end.

Larvae: Legless, headless, up to 6 mm long at maturity, milky-white.

Pupa: 3 mm long, brown, football-shaped, two stalks with small finger-like projections on ends.

Life History

SWD overwinter as adult flies. In spring flies become active and lay eggs in ripening fruit. Based on climate model predictions, there could be up to 5 generations per year in BC. Generations overlap as flies are relatively long-lived particularly at temperatures of 20°C and cooler. Based on Japanese literature, a female can lay eggs for 10-59 days, with 7-16 eggs laid per day, and average 384 eggs per female. Eggs hatch in 2-72 hours, larvae mature in 3-13 days, and pupae reside in fruit or outside of fruit for 3-15 days. In the lab at constant temperature, one generation takes 50 days at 12°C, 21-25 days at 15°C, 19 days at 18°C, 8.5 days at 25°C, and 7 days at 28°C. Adults are attracted to and feed on ripe and decaying fruit.

Monitoring

Flies can be monitored with cup-like traps baited with apple cider vinegar. Place traps when the temperature is consistently over 10°C and/or before fruit starts to ripen. Hang traps in the plant canopy in a shady location. Check traps once per week and look for the SWD adults in the bait solution. Use a hand lens or other magnifier to see the female ovipositor. Replace the bait solution each week. Suspect fruit can also be collected and inspected for larvae.

Management

Cultural control

Where practical, remove or bury cull fruit to eliminate additional feeding and breeding sites. Keep equipment and processing areas free of old fruit. Think beyond the borders of your farm and be aware of host plants in adjacent fields. Encourage neighbours to also manage for SWD. Shorten picking interval where possible: pick early, clean and often.

Biological control

To date, there are no commercially available biological controls for SWD. Research is underway to identify potential predators and/or parasites that may be useful in managing SWD.

Chemical control

Chemical control will be required if trapping shows that adult SWD flies are present in the field when berries begin to ripen. Adults are the target and are killed by direct spray contact and/or when they are exposed to residues of insecticide on the treated fruit and leaves.

Consider the following when planning a spray program:

1. All of the recommended products are toxic to bees. Avoid application when crops are blooming and bees are in the field. If sprays are necessary during this time, they should be applied at night.
2. Use enough water and pressure to ensure adequate coverage. Flies prefer to feed in the lower, shaded part of the canopy.
3. Use spray equipment that will allow effective coverage. Consider crop training and use of trellis wires to improve sprayer access to crop. Currently, no products are registered for aerial application.
4. To limit development of resistance, rotate between the recommended products.
5. A 7 – 10 day spray interval may be necessary to protect fruit through the ripening period depending on temperature and pest pressure.

6. A post-harvest spray may be necessary to prevent flies from building up on residual fruit and spreading to adjacent later ripening crops.

The following products are registered for SWD control:

Delegate WG (25% spinetoram) at 315 to 420 g/ha (126 to 168 g/acre). Do not apply more than 3 times per season. Allow a re-treatment interval of at least 7 days. Do not apply within 3 days of harvest; or

Exirel (100 g/L cyantraniliprole) at 1000 to 1500 mL/ha (400 to 600 mL/acre) in enough water to obtain good coverage. Do not apply more than 4 times per season or a maximum of 4.5 L/ha (1.8 L/acre).  Tank mixes and sequential applications with strobilurin (Pristine, Cabrio), copper and captan fungicides are not recommended as crop injury has resulted under lab settings. Do not apply within 3 days of harvest; or

Entrust SC (240 g/L spinosad) at 333 to 444 mL/ha (133 to 178 mL/acre). Minimum re-treatment interval is 5 days. It is OMRI approved for organic production. Do not apply more than 3 times per year and do not apply within 3 days of harvest.

The following products have received emergency registration for SWD for 2017:

Capture 240EC (240 g/L bifenthrin) at 300 to 450 mL/ha (120 to 180 mL/acre) in enough water to obtain good coverage of foliage. Use the higher rate when canopy is heavy and/or pest pressure is severe. Apply between June 1 and August 31, 2017. Do not apply more than 2 times per season.  Do not make applications less than 7 days apart.  Do not apply within 3 days of harvest; or

Malathion 85E (85% malathion) at 1.0 L/ha (400 mL/acre) in up to 1000 L/ha of water. Apply when the temperature is 20°C or more. Apply between June 1 and November 30, 2017. Do not apply more than 3 times per year. Do not apply within 2 days of harvest.

For more information see supporting document: Spotted Wing Drosophila Brochure

WEEVILS

Clay Coloured, Black Vine, Obscure, & Strawberry Root Weevils

Hosts

Almost all small fruits and ornamentals.

Damage

Roots. Larvae feed on and girdle the roots, rootlets and basal crown area and are especially harmful to young plants. The larvae are the most damaging stage.
Leaves. Adults feed at night on leaves, notching the leaf edges.


Bush. Stunted, poor yields, and may die.

Identification

Blueberries are mainly attacked by black vine weevils. The following description is for this insect. Obscure and strawberry root weevils have similar life cycles to black vine weevils and are about one-half the size.

Larva. White with brown heads, legless, C-shaped, up to 1.3 cm long when fully grown.

Adult. Black to grey-black beetles with curved snouts, often orange or yellow specks on wing covers, about 1.3 cm long, and a hardshelled body.

weevils

Life History

Overwinters in the soil as larvae or as adults. Adults emerge from the soil beginning in late April. Large numbers emerge in late June. The beetles do not fly but are strong walkers and invade new plantings during July and August. They begin to lay eggs in or on the soil in early June and continue until mid-September. Upon hatching, the larvae work through the soil and begin feeding on the roots.

Monitoring

Start to watch for characteristic leaf notching in late April. Be especially observant in early May and early July of bushes that are close to older plantings or weedy headlands.

At night, inspect foliage of plants with notching using a flashlight, especially on warm, still evenings. Adults will readily fall from the bush — place a white sheet under bush and shake vigorously. During the day, inspect under plant debris and in cracks in the soil. Lay boards on the soil for weevils to hide under. Lift up every few days and inspect for adults.

Management

Cultural control

Check the field history before planting. Root weevils will attack newly planted blueberries if present on the previous crop grown in the field. To reduce weevil population, plant infested fields to a non-host crop, such as cereal cover crops, for 12 to 16 months before planting blueberries.

Plant stock that is free of weevils.

Control weevils in vegetation and ornamentals planted adjacent to the blueberry field, if appropriate.

Chemical control

Apply control measures only if leaves have fresh leaf notches. For best results, begin an adult control program when most of the adults have emerged from the soil in the spring to early summer but before they begin to lay eggs. It can take 3 to 5 weeks from emergence to egg laying.

Exirel (100 g/L cyantraniliprole) at 1000 to 1500 mL/ha (400 to 600 mL/acre) in enough water to obtain good coverage.  Use the high rate when pest pressure is heavy. Do not apply more than 4 times per season or a maximum of 4.5 L/ha (1.8 L/acre).  Tank mixes and sequential applications with strobilurin (Pristine, Cabrio), copper and captan fungicides are not recommended as crop injury has resulted under lab settings. Do not apply within 3 days of harvest; or

Actara 25WG (25% thiamethoxam) at 210 to 280 g/ha (84 to 112 g/acre) in sufficient water to obtain coverage of foliage. Apply when weevils or weevil damage is detected. Repeat application if insect populations rebuild. Use the higher rate for heavy infestations. Do not apply more than twice per season. Do not apply within 3 days of harvest; or

Note: This product is highly toxic to bees exposed to direct treatment or to residues on blooming crops and weeds. Do not apply Actara or allow it to drift onto blooming plants if bees are visiting the treated area. After application, wait at least 5 days before placing bees in the treated field.

Malathion 85 E (85% malathion) at 1.0 L/ha (400 mL/acre) in 1000 L/ha of water. Spray bushes for thorough coverage. Do not apply within 1 day of harvest; or

Admire as applied for aphid control will also help to suppress weevils if adults are present at time of spraying.

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